In my last post, I described in some detail the importance of sleep on the brain and the mind. I also discussed suggested some do’s and don’t’s for getting a decent nights sleep. One of the factors that I did not explore was the benefits of exercise on sleep, the brain and the mind. I wanted to address that in this post as well as the other benefits that exercise has on the brain and the mind.
CALORIES AND EXERCISE
The basic unit of measurement of everything we eat and drink are measured in calories. Calories even more specifically refer to the amount of energy we consume through physical activity. For example, a banana may have 90 calories and going for a brisk one-kilometre walk may burn 70 calories.
A calorie is the amount of energy needed to raise one gram of water by one degree celsius. Calories are required by the body in four major ways:
- to keep the body’s cells, tissues and organs at resting state (alive)
- to heat the body
- to digest food
- and to fuel mental and physical activity
The calories burned for the first three activities are pretty much a fixed amount. It is the energy needed for mental and physical activity as well as the number of calories consumed that determines a person’s weight.
TYPES OF EXERCISE
The two categories of exercise that are fueled by calories are anaerobic and aerobic exercise.
Anaerobic exercise includes exercises such as weight lifting, pull-ups and pushups. These and other similar types of exercise are used to promote strength, power and speed. These forms of exercise are called anaerobic because they involve going beyond the muscle’s capacity to burn oxygen for energy. When you do this you feel the familiar burn of lactic acid in your muscles.
Aerobic exercise are exercises, like running, cycling, swimming and brisk walking, that are sustained over a long distance at a moderately high level of intensity. The emphasis of aerobic exercise is on exertion. This means getting your heart rate up high enough that you feel out of breath, sweat, and feel physically exhausted.
Aerobic literally means ‘with oxygen’. It refers to the use of oxygen being consumed in the energy-generating process in muscles. This process involves using oxygen to burn sugar (i.e. carbohydrates) and fat. The first to burn is the sugar glucose that floats free in your blood stream. The next to burn is glycogen that is sugar stored in your muscles and liver. Finally, oxygen is used to burn stored fats and free fatty acids and triglycerides floating around in your bloodstream. All this ‘burning’ of sugars and fat becomes adenosine triphosphate (ATP) , the primary energy currency for every cell in our bodies.
In the first stage of aerobic exercise, glycogen is broken down into glucose to convert into ATP. After about 30 minutes when the the body has burned through it’s glycogen storage and any remaining glucose in the bloodstream, the body begins to burn fat for its energy source. When the fuel source changes from glucose to fat, runners call this switch ‘hitting the wall’ and there is a noticeable drop in performance.
YOGA AS EXERCISE
There are definite benefits of yoga on the brain and the mind. Firstly, in the sense of triggering the rest/digest branch (the parasympathetic nervous system) of your autonomic nervous system making you feel calm and relaxed. Secondly, the mental benefits of meditation on keeping you focused and present. However, yoga doesn’t provide the biochemical benefits that aerobic exercise gives us as I outline below.
EXERCISE, ANXIETY & STRESS
You can ask almost any medical doctor and they will tell you that exercise is one of the best ways known to hammer anxiety, crush stress, rebalance moods and increase positive feelings. Exercise creates chemical responses in our brains that lead to temporary and, most beneficially, long-term mental health.
When we feel negatively stressed or anxiety-ridden we can feel and experience a number of things:
- cold or sweaty hands and feet
- heart palpitations
- shortness of breath
- high-blood pressure
- feelings of fear, dread, panic, uncertainty or uneasiness
- sweating
- reduces or even negates appetite
All of these symptoms of stress are due to certain chemicals swimming through our brains and bodies. Adrenaline is the stress hormone that raises your heart rate and boosts your blood pressure. Cortisol is the stress hormone linked to feelings of fear, dread and uneasiness. these chemicals have a direct affect on your mood and motivation, supresses your digestive system and alters your immune system. As a side note, high levels of cortisol are associated with an increased risk of developing type 2 diabetes. Increased levels also have deleterious effects on the hippocampus significantly impairing the ability to learn and form new memories.
Exercise, especially aerobic exercise, is a brilliant way to burn off any excess adrenaline and/or cortisol swimming in your bloodstream. On top of this, there is a growing amount of evidence that it has strong anti-anxiety effects by changing the brain in a multitude of ways. This is the reason why so many doctors prescribe exercise as a treatment for anxiety.
Let’s take a moment and look at the benefits of a 30 minute brisk walk, a 20 minute jog or any other exercise that gets your heart pumping and your sweat glands working. The brain begins to generate neurotransmitters (brain-chemicals) such as GABA, acetylcholine, serotonin, dopamine, and norepinephrine, which keep us energized, calm and positive.
GABA is the major inhibiting neurotransmitter in the brain and which has strong calming effects on the mind. Exercise has the same effects like Valium and Ativan (benzodiazepines) that work on the GABA system to create a sense of calm. But like these drugs, exercise has no side effects or negative addictive qualities.
Acetylcholine is the neurotransmitter key to memory and attention. Alzheimer’s disease is marked by a significant decrease in acetylcholine level.
Serotonin is the neurotransmitter that give us a sense of well-being and hopefulness. It’s levels increase when the body breaks down fatty acids to fuel the muscles. Low levels of serotonin are linked to some forms of depression.
Dopamine is the ‘feel good’ neurotransmitter It is responsible for a sense of pleasure, success, achievement and even euphoria.
Norepinephrine is the neurotransmitter that allows us to focus and shift our attention. It also works with dopamine to help us ‘feel good’.
BDNF (brain-derived neurotrophic factor) is a protein substance is produced as a result of aerobic exercise. It is responsible for many functions, such as consolidating the connections between neurons; promoting myelin growth to make neurons fire more efficiently,; and generating new neurons in the hippocampus from stem cells.
Endocannabinoids is the chemical compound that plays a key role in processing appetite, mood, memory and pain sensation. It is also key to reducing the hormones that trigger the HPA axis, (which plays a significant role in the fight/flight response of the reactive mindset).
Endorphins are natural neuropeptides that bind to opioid receptors in the brain and have potent pain-killing effects. Often referred to as the ‘runner’s high’.
Many of my clients have stressful jobs and a majority of them find it difficult to unwind when they get home. If you are not one for the gym or like running, then take a brisk walk. Walking requires very little in the way of sports equipment and can be done almost anywhere. Even a 10 minute brisk walk will give you 90 minutes of energy and burn any excess cortisol.
A GOOD TIME TO THINK & LEARN
The timing of learning is important when exercising. If you are going to do any thinking or learning while your run, cycle or swim it is best to do it at the start of your training. After about 30 minutes into your aerobic exercise, blood is directed away from your prefrontal cortex (the home of your higher thinking) to help your body deal with the demands of your physical exertion. After you finish exercising, the blood shifts back to your prefrontal cortex. This is also a perfect window for clearer thinking and easier learning, because of the increased capacity for focus.
OTHER BENEFITS OF EXERCISE
- exercise lowers bad (LDL) cholesterol and raises good (HDL) cholesterol, which prevents arteries from getting stiff and narrow
- lowers blood pressure
- promotes repair mechanisms to deal with physical stress that not only promote recovery but strengthen the entire body, including the brain
- makes the heart beat more efficiently
- boosts the body’s sensitivity to glucose, which lowers the risk of diabetes
- increases levels of dopamine, norepinephrine, and serotonin that provide you with the neurochemistry to not only boost your energy but keep you calm and focused
- brisk walking for just 3 hours a week is enough to generate new brain cells in your frontal lobes, your hippocampus, and the corpus callosum
- lowers a compound in blood that makes blood clots called fibrinogen and thus lowers the risk of stroke
MOVING TO ACTION
Now that we are aware that exercise helps with stress, anxiety, depression and improving sleep, it is time to apply the science. So get out there, lace-up, hit the gym, jump on your racer or whatever your thing is and generate a good sweat! It’ll do wonders for you.
